Is it okay to feel this way?

Because of all the bad experiences I had, I notice all little changes in person's behavior. That being said, I almost always have panick attacks during or after sex. I don't know why during, but after sex I get it because I'm scared of being left alone. My boyfriend of many years knows it and it's one of the reason s we'd cuddle after sex. I know it is not his obligation to deal with my mental problems, but I considered cuddles normal and it helped me stop panick attacks till recently. Recently (few months) he'd just go do his own thing, and it's not even anything important. He'd just go in another room without a word and watch tv, or something like that. I tried asking him to cuddle me again, at least for a bit, because I feel really bad and depressed and just used if he leaves me like that. He said okay, but I don't remember last time he cuddled me... Today we also did it, few hours ago. I was giving him bj at the end and after he finished I suddenly had to throw up and he got quiet; I tried hugging him, asking if it was okay, I said I'm sorry for ruining the mood with sickness; he just sat far on the edge of the bed, didn't say a word to me and went to sleep. I'm not even sad, I just feel lonely and used so I'm writing this. Is it okay to feel this way?

Also if anyone has any idea how to deal with it, I'd be very grateful because I don't know what to do anymore.

PS English is not my native language so sorry for the mistakes